This prospective, double-blinded randomized controlled trial assessed interim outcomes comparing conventional jig-based unicompartmental knee arthroplasty with navigational control (CO UKA) and robotic arm-assisted unicompartmental knee arthroplasty (RO UKA) in patients with symptomatic medial compartment knee osteoarthritis. The study evaluated surgical accuracy of component placement, early functional recovery and inpatient parameters, validated patient-reported outcome measures, and complications. Outcomes were predefined and recorded at scheduled intervals for up to two years after surgery.
A total of 107 patients with symptomatic medial compartment osteoarthritis were prospectively randomized to two treatment arms: CO UKA (n = 52) and RO UKA (n = 55). The report covers the currently available recruited cohort and presents interim findings. Demographic and baseline characteristics beyond the total randomized numbers were not reported in the abstract.
All patients underwent preoperative CT-based surgical planning. Procedures in both groups were performed by the medial parapatellar approach. The operative pathways included standardized perioperative care and a uniform postoperative rehabilitation programme applied to both treatment arms. Specific implant types, intraoperative time, or additional surgical details were not reported in the abstract.
Predefined study outcomes included: accuracy of femoral and tibial component position relative to the preoperative plan; inpatient recovery metrics such as pain scores, opioid analgesia consumption, and length of hospital stay; and patient-reported outcome measures including the Oxford Knee Score, Knee Injury and Osteoarthritis Outcome Score (KOOS), Western Ontario and McMaster Universities Arthritis Index (WOMAC), and the Forgotten Joint Score (FJS). Outcomes were recorded at regular intervals for two years postoperatively.
RO UKA demonstrated superior accuracy in executing the planned component positions for both the femoral and tibial implants, with statistically significant differences compared with CO UKA (both p < 0.001). In addition to improved implant-placement accuracy, RO UKA was associated with improved early inpatient recovery: reduced inpatient pain scores (p < 0.001), decreased inpatient opioid analgesia consumption (p = 0.008), and a shorter length of hospital stay (p = 0.004) relative to CO UKA. The abstract does not provide specific numeric values for the magnitude of these differences, only the reported p-values.
At two-year follow-up there were no statistically significant differences between RO UKA and CO UKA in several commonly used measures of knee function and symptoms: the Oxford Knee Score (p = 0.299), KOOS (p = 0.261), and WOMAC (p = 0.281). However, the Forgotten Joint Score (FJS), a measure sensitive to patients’ perception of joint awareness, favored RO UKA with higher scores at six months (p = 0.002) and at two years (p = 0.021). The abstract does not report absolute score values, confidence intervals, or minimal clinically important differences.
During the study, patient recruitment declined as an increasing proportion of eligible patients expressed a preference for RO UKA. Operating surgeons also reported reduced clinical equipoise between the two treatments. These factors were noted as affecting ongoing recruitment and represent important contextual limitations for completion of the trial and interpretation of interim findings.
Several authors disclosed relationships with industry and funding sources. Disclosures included fellowships and scholarships, institutional research support from industry (including Stryker), grants or contracts from multiple orthopaedic companies and research bodies, royalties and consulting fees, and payments for educational activities. The abstract states these declared interests were unrelated to this specific study. Full conflict statements are included in the source record.
In this interim analysis of a randomized, double-blinded trial, robotic arm-assisted unicompartmental knee arthroplasty (RO UKA) was associated with greater accuracy in achieving planned femoral and tibial component positions and with improved early inpatient recovery metrics—lower pain scores, reduced opioid use, and shorter hospital stay—compared with conventional jig-based UKA with navigational control (CO UKA). Standard functional outcome measures (Oxford Knee Score, KOOS, WOMAC) showed no difference at two years, while the Forgotten Joint Score favored RO UKA at both six months and two years.
These results suggest that robotic assistance may improve technical accuracy and certain aspects of early recovery and patient-perceived joint awareness, though many commonly reported functional outcomes were equivalent at two years in this interim cohort. The trial experienced recruitment challenges owing to patient preference and evolving surgeon equipoise, which may influence final sample size and interpretation of long-term comparative effectiveness. The abstract does not provide detailed numeric outcome values or long-term revision data; those details were not reported in the source abstract.
Clinicians interpreting these interim findings should note the reported benefits in component placement accuracy and early recovery with RO UKA, balanced against similar scores in standard outcome measures at two years. The disclosed author relationships with industry are documented in the source and should be considered when assessing the study context. Further details, including complete outcome tables, baseline characteristics, and longer-term follow-up, were not provided in the abstract and would be necessary to fully evaluate clinical impact and cost-effectiveness.